Apple Fitness+ is coming to iPhone iOS 16.1 on Monday, October 24.
"Next Monday, October 24, Apple Fitness+ is coming to iPhones with iOS 16.1, so users in 21 countries can use the service without needing to buy an Apple Watch.

Apple also announced today an Artist Spotlight series featuring Taylor Swift songs from her new album “Midnights,” a new yoga workout program with ultramarathon athlete Scott Jurek and more ways to get a Fitness+ subscription at no additional cost.

With iOS 16.1, Fitness+ can be found in the Fitness app, which is located in the middle tab of the iPhone. Once signed up, users can experience Fitness+ on iPhones, iPads and Apple TVs. Subscribers can also AirPlay workouts onto third-party devices like Roku."